Hmm, where to start with this one. First off, please note that all the testing was done on a 1978 CVCC and motorcycles. With modern day cars monitoring the vacuum in the intake, what do you think is going to happen if you start introducing any amount of air or air/water/methanol into the intake? I see some P0171/0174 engine codes coming in. If they don't come in, then you are not introducing enough to make it worthwhile.
The other issue I see is that the article is very specific that it helps to reduce exhaust temps (by conversion of the water to steam). one problem with this, the cat in the exhaust needs to be as hot as possible to efficiently convert CO to CO2 and burn the unused fuel. Drop the temp too much and you can risk failing emissions tests if they do them in your area, if not tossing engine codes for the exhaust not being clean enough.
You would be better off converting the truck over to a 100% ethanol system. Sure, you have to spend about $500 on a conversion kit, but once you do this, you get more power out of the engine (as the fuel burns in an 8:1 ratio compared to the 14.7:1 of gas) and because ethanol is cheaper than gas, your cost at the pump really goes down as you are spending less overall on fuel. Yes, your mileage goes down, but not by as large of a factor as the price difference between gas and ethanol.
I would say to give it a try, but I think you are going to find that to get the "6% gain" is going to result in engine codes and to get a working system that doesn't throw codes, the gains are going to be very negligible. But then, this is just my engineering mind at work. The other "question" that I would ponder to you is that if this is such an easy way to improve efficiency of the engine and costs so little to fabricate, then why isn't this system on all new cars. The automobile manufacturers are fighting to meet the new requirements. Why wouldn't they add this on to the cars?
